


A First Time For Everything

by Lopsided_Whiskey_Grin



Category: Supernatural
Genre: Alpha Dean Winchester, Alpha/Beta/Omega Dynamics, Alpha/Omega, Bonding, Castiel in Heat, Dean Has a Sexuality Crisis, Destiel - Freeform, Explicit Sexual Content, First Time, Knotting, M/M, Marking, Mating Cycles/In Heat, Omega Castiel, Omega Castiel/Alpha Dean Winchester, Omega Verse, season 5
Language: English
Status: Completed
Published: 2016-10-10
Updated: 2016-10-10
Packaged: 2018-08-20 13:58:59
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,592
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8251624
Author URL: https://archiveofourown.org/users/Lopsided_Whiskey_Grin/pseuds/Lopsided_Whiskey_Grin
Summary: Set in Season 5 episode 3 "Free to Be You and Me". Dean and Cas are driving across state lines to find and interrogate Raphael and Cas, who hasn't been in Jimmy's body very long, goes into heat. He has no idea what is happening to him. Of course Dean, an Alpha, knows. But Dean has his reservations, since he hasn't ever worked a male through a heat, because hey Dean is not 'gay'. Cas doesn't have anyone else though, so what is there left for Dean to do but help?





	

It was somewhere around nine months after Cas had pulled Dean from Hell that Dean found himself taking the angel on a long overnight drive from Greeley,  Pennsylvania to Waterville, Maine. The trip had been Cas’ idea. He needed Dean's help in trapping and interrogating Raphael to find God's location. The actual drive had been Dean's idea; there was no way in  _ hell  _ he'd let Cas zap him anywhere anymore after what happened the last time. Having to take laxatives for a week to get regular again? Thanks but no fuckin thanks. 

Overall the journey to Maine hadn't been too bad so far, Dean admitted to himself. He loved being on the open road and the full moon was out and shining somethin’ fierce and beautiful on the passing scenery. All the trees and fields whipping by were coated in a muted silvery sparkle that lent to Dean a peaceful calm he hadn't known since before he and Sam decided to go their separate ways. And it was kind of nice to have someone riding shotgun with him again… even if that someone was fidgeting like an impatient little kid. 

“Dude, Cas, just relax. I know you're all amped up to grill Raphael but we'll get there when we get there. Sit back and enjoy the ride, all right?” Dean glanced over at Cas to give him an encouraging smile but Cas just looked away from him and out the window, huffing out a sigh and hooking his finger behind his tie to loosen it. 

Dean shook his head and let out a little chuckle. “I think it's time I introduced you to my friend Skynrd,” he said, pushing play on his cassette deck. “Nothing like some ‘Simple Man’ to calm the nerves.” 

The music started playing softly and Dean hummed along, flipping his blinker to drive into the passing lane to get around a slow moving semi. The last time he had listened to this song he had been alone in the Impala and pissed at Sam and more than a little lonely. 

Now, though, his spirits were somewhat lifted; he actually felt like he had a job to do, some purpose in helping Cas catch Raphael -- and the fact that he wasn't by himself helped too. He sometimes hated the unspoken edicts that said Alphas generally preferred to be loners. Dean much more preferred to be around the others in his little hunter pack of Bobby, Ellen, Jo, and Sam. And he was warming up to Cas more and more too now, but not in a romantic or chick-flick way, not like he was gay or anything. There was nothing against appreciating a guy’s eyes or hair or his bodybuild though, right? He was pretty certain Cas racked up the girls fairly regularly with those looks. 

That gave Dean pause. Was Cas’ vessel even capable of responding to the desires other people experienced or was the angel inside blocking those out? As a matter of fact, Dean wasn't really sure if Cas was another Alpha like him or if he was possibly Beta or even Omega. Dean had a pretty good track record of being able to pick out a person's dynamic before they told him; he just had a knack for it. But Cas was different. Cas was just  _ Cas. _ He didn't have any of the same mannerisms that were typical of  _ any  _ of the dynamics -- he never displayed any shows of dominance and Dean didn't think he ever once saw him duck his head down or bare his throat in submission. Dean didn't know why he hadn't noticed it before. He supposed it was because he never really thought so much about it. 

He was about to be thinking of it a hell of lot more though shortly.

The opening of the passenger window caught his attention. He thought maybe Cas was going to crack it a little to let some fresh air in but then he kept rolling it down until it was all the way open. Chilled summer night wind came blasting in and swept around the interior of the Impala and whipped up old receipts and fast food napkins in a crumpled paper hurricane. 

“Jesus, Cas! What the fuck? Wanna roll that up a little?” he asked, looking over.

The sight of Cas made his breath catch painfully in his throat. He was curled toward the door with a heated blush darkening his cheeks and a sheen of perspiration slicking his top lip. And then the scent hit Dean's nostrils like a freight train with the next violent gust of wind that blew in. He momentarily drifted into the oncoming lane before swerving back onto the right side of the road. 

“Cas?” he broached carefully, his voice suddenly unsteady. 

Cas looked over at him, brows drawn together in a confused sort of misery. “Dean, what is happening to me?” He drew his trench coat tightly around himself and began to shiver as the wind continued to whip through the open window and ruffle his hair. 

Dean knew exactly what was happening to him. “Are you telling me you've never been in heat before?” He flexed his fingers over the steering wheel and looked back to the road, trying to focus on driving and trying  _ not  _ to think about how absolutely incredible Cas smelled. 

“What does ‘in heat’ mean?” Cas asked. 

Dean thought Cas must have been joking and he barked out a little laugh. But when he glanced over, Cas’ face was nothing but earnest. Dean swallowed hard and looked back to the road. “It's when an Omega needs to...needs to…” he stalled out, blushing. Rubbing a hand over the back of his neck, he tried again. “Didn't your vessel ever have one?” 

Cas was quiet for a moment except for little panted breaths, seemingly consulting with the human spirit inside. He shifted gingerly in his seat and rolled up the window. “Jimmy says he used to go into heat regularly and his wife worked him through it. I have never had one at all since being in this body. Angels have no need for such an experience in heaven.”

Dean didn't know what to say. He looked to the road then back to Cas then back to the road. The heavy scent of Cas’ heat was suffusing through the interior of the car now that the window was closed and Dean felt his dick start to get hard in his jeans. He shifted in his seat to relieve some of the pressure. Alarm bells hadn't really started going off in his head  _ yet;  _ there was no Alpha alive who didn't have a reaction to that smell coming off a male, even the heteros like himself. 

Cas groaned, wrapping his arms about his middle and curling forward. “Dean, please help me,” he rasped. 

Dean pulled his right hand off the wheel and brought it down on Cas’ shoulder to try to comfort him. He could feel, even under all the layers of his clothes, that Cas was already burning up and was way too far gone for emergency suppressants. This was not good. If Dean couldn't get him to a willing Alpha or even a Heat-house soon, Cas would be in agony.

Cas trembled under Dean's touch and let out a weak moan. “Okay, okay,” Dean said soothingly, rubbing his hand up and down Cas’ arm. “There's a town about 20 miles down the road. I'll get someone to help you as soon as we get there, I promise.”

Cas turned to him them so abruptly that Dean drew his hand back in surprise. “No, Dean, now!” he cried desperately. “Whatever you need to give me to so I can have relief, I need it from you now.”

“I- I can't do that, Cas,” he stammered. “I don't swing that way.” 

“Swing what way? Dean, please, I'm begging you.” He looked at Dean miserably then curled forward again with a moan. 

Dean squeezed the steering wheel, staring out at the passing landscape and trying desperately to think of another option they might have. “I'm not gay,” he said firmly.

He had worked plenty of Omega women through in his life, definitely, and plenty more females when they weren't cycling, just for the fun of it. And in his heart of hearts, yeah okay, he had entertained the idea of taking a guy to bed, but never one in  _ heat.  _

“You doing this for me has no bearing on your sexuality, Dean, I swear. This pain is unbearable. It must be you and it must be now,” he panted. 

Dean swallowed and raked a hand roughly through his hair. Cas’ cloying scent was clouding his brain, blocking out rational thought. Every goddamn instinct in his body demanded that he fuck into Cas as soon as possible and knot him as deeply as he could.

_ Take, claim, breed.  _

Pulling in a deep, shaking breath, Dean veered off into the next road they came upon, hardly tapping the brake. A car that had been following him nearly clipped the Impala’s bumper and blared their horn. Dean barely noticed at all. His mind was racing, with each thought clamoring louder and louder for attention.  _ I'm just helping Cas out. Just doing this for a friend. Doesn't really mean anything. No one has to know. This'll just be between the two of us. I wonder how it's going to feel? Different, obviously, but different how? What if I end up liking it? Don't lie to yourself, Dean, you've always wanted to do this. And you know you can hardly keep your fucking eyes off Cas when you're in the same room together. _

A house came up on the right after Dean guided the car around a tight corner and he huffed out a relieved sigh. It was nestled in a thick grove of evergreens and all the windows were dark and held no signs of life. It looked to be one of the vacation homes the tourists rented out over the summer, but with the start of the cool Fall months gearing up, it now stood empty. 

Cas let out a confused whimper when he looked up and saw that Dean was pulling into the driveway. “Where are we?” he asked, his voice a deeper octave than Dean had ever heard before. 

Repressing a shiver, Dean put the car in park. “This is going to be our home for the next 24 hours,” he replied. 

Cas nodded his understanding eagerly and fumbled for the door handle. Dean got out and made his way around to the passenger side to help him up to the porch. Cas lurched out of the car as soon as the door was open, falling into Dean's arms with a grunt. The cloud of Omega hormones that came with him was intoxicating and Dean had to fight very hard to keep his knees from buckling. 

“All right, buddy, let's get you inside, okay?” He tried to chuckle to keep the mood light but it fell flat. 

They started making their way to the door with Dean’s arm looped over Cas’ shoulders to guide him, but Cas stopped abruptly. He bent forward, bracing his hands on his knees and let out a desperate and pained cry. The sound shook Dean right to his core. 

“Nice, deep breaths, Cas,” he soothed, rubbing his hand over his back. “We're almost there.” 

Cas trembled and said, “I think I'm going to be sick,” and then promptly dry heaved a couple times. 

Dean's brows knit together in worry. Cas’ heat was progressing way too fast and was far stronger than any Dean had seen before. Maybe it had to do with how long he had been in Jimmy’s body or the fact that his angel juice had been blocking out the Omega hormones that whole time, but either way it most likely meant it would take longer for Dean to work him through it. Primal and ancient desire arrowed straight to Dean's guts at the thought and all he wanted was to take care of this Omega, to make him feel safe and comfortable, to make him feel good, to break his heat. 

The reasons why he shouldn't be doing this didn't really seem all that clear anymore. The line between gay and straight and even bi was blurred so damn much; at the moment Dean couldn't be bothered to care. His only driving desire was to give Cas relief and the only way to do that was through his knot. 

“Okay,” Dean said, “you just wait here a minute and focus on breathing. I'm going to get this door open for us.” Sprinting up the porch steps, Dean fished his lock pick kit from his jacket pocket. He made quick work of the lock then ran back to help Cas up the steps.

They made their way into the house slowly and Dean peered through the darkness to try and locate a bedroom, preferably one on the first floor; more stairs would be nearly impossible for Cas to navigate again. He spied an open door at the end of the entryway hall that looked promising and he helped to shuffle Cas in that direction. A large master suite awaited them, replete with a king sized bed and a huge soaking tub across the room through an arched opening in an adjoining bathroom. 

Cas whimpered out a weak sigh at the sight before them and staggered his way to the bed with Dean's help. He sunk down onto the soft mattress and slumped his hands down into his lap. Soft beams of moonlight filtered in through the expansive plate glass windows behind the bed, highlighting the tips of Cas’ dark hair with a beautiful shimmer that took Dean's breath away. And when Cas looked up at him with his brows drawn together in an indescribable mixture of uncertainty and unabashed arousal, Dean felt his heart spasm painfully in his chest. 

“What now, Dean?” Cas asked. 

Dean paused. “Jimmy didn't tell you?” Dean stepped to the end of the bed where Cas sat, his dick aching in his jeans. 

Cas shook his head, swiping a bead of perspiration from his temple. “He wouldn't show me what went on between him and his wife -- said it was private.” He wrapped his arms around his stomach and grimaced as another wave hit him.

Dean had had enough of seeing Cas in this misery, his own fragile sexuality be damned. He knelt down in front of him, spreading his knees gently so he could get in close. “All right,” he began, surprised at how even his voice sounded when he felt like he was about to vibrate right out of his skin. “I'm going to start by undressing you and then we'll get down to the fun stuff.”

He began undoing Cas’ tie then pulled his coat from his shoulders. Cas watched his every move, his plush lips parted as he panted softly. “Fun stuff?” he breathed. His body trembled under Dean's touch and the scent of his heat grew impossibly stronger. 

Dean cleared his throat, his eyes drawn helplessly to the throbbing bulge between Cas’ legs. He forced his gaze back up. “The only way to break your heat is for me to knot you.” 

Cas’ Adam's apple bobbed and Dean knew he must have some sort of primal recognition of what that meant. Pushing to his feet, Dean helped Cas to stand and continued pulling his clothes off. He had just gotten Cas’ slacks unbuttoned when Cas reached out and started pawing at Dean's t-shirt, awkwardly trying to pull it up over his head. 

“You're taking too long,” he rasped at Dean's surprised look. “Need you  _ now.” _

Dean did not have to be told twice. He peeled Cas’ sweat-soaked shirt from his shoulders then tugged down his pants and underwear with one jerk. The plain white boxers Cas had been wearing were drenched and Dean's belly tightened up in response. 

Cas blushed when he saw Dean staring down at the saturated fabric in his hand. “I- I'm sorry,” he said, clearly embarrassed. 

Dean's eyes flew back up to Cas’. “Don't be sorry, Cas. Don't ever be sorry. This is the hottest fuckin thing I've seen in my life.” And it was true; somehow those pristine and dripping boxers were even sexier than a wet pair of panties. Dean knew he should be worried for thinking like that, but he was so far beyond caring about something so trivial as his supposed heterosexuality at the moment that it didn't even register. 

Taking a deep breath, Dean stepped back a little and managed to pull his own clothes off despite his suddenly uncoordinated hands. Cas watched as he stood before him, gloriously naked and glistening in sweat and moonlight, his thick veiny cock hard and sticking straight out from his body. A gleaming dribble of slick was trailing down the insides of both his thighs, pummeling Dean with a heavy kick of arousal right to his gut. 

His heart tumbled in his chest and he lunged forward, framing Cas’ face with his hands and smashing their lips together. Cas went rigid for a moment in surprise then melted against Dean's body. His mouth opened with a little coaxing from Dean's tongue and he moaned. The sound was like the sweetest music to Dean's ears. 

Kissing Cas was unlike anything he had ever experienced before and his senses were immediately overloaded. It was all hard angles and scratchy stubble and tastes and smells that were wholly male and wholly Omega. Gone were the soft curves and long hair and gentle gasps that Dean had been accustomed to -- in their place were deep rumbling groans and a strong grip and a hard on. 

Cas’ large hands found their way to Dean's hips, pulling him even closer. His slick, hot skin slid against Dean's and their cocks brushed together and Dean almost lost his goddamn mind. “Get on the bed,” he commanded, his ingrained Alpha side slipping through the cracks of his control. He had been trying to hold it back so as not to scare Cas when it was only his first heat, but it was getting difficult to suppress it. 

But Cas responded without question, seemingly needing to hear it just as much as Dean needed to say it. He obeyed Dean's words at once by crawling up onto the bed on his hands and knees, sinking his head and chest down and presenting his ass. A fresh blurt of moisture dripped from Cas’ quivering hole as Dean watched and Dean nearly came then and there. Taking his aching dick in hand, he squeezed the base to stave off his orgasm; coming now, before he was buried inside Cas would be no benefit to the Omega.

But he didn't want it like this, with Cas on his knees. It was a first time for both of them in a way and Dean desperately wanted to see Cas’ face when he came. “Roll over,” he said gruffly, propping a knee up on the plush mattress.

Cas moved onto his back, putting his feet flat on the bed, looking up at Dean with an unquestioning trust that ripped right through his chest and left him breathless. Spreading Cas’ legs nice and wide, Dean kneeled between then hooked his ankles up on his shoulders to get unimpeded access to Cas’ dripping hole. 

“Ready?” Dean asked, wondering if he was maybe asking himself; there was no going back from this. But did he really want to? He felt more and more, with each passing second, that he had maybe been trying to convince himself his whole life that he didn't want this. It just took falling for Cas for him to finally come to grips with it the fact that he'd been lying to himself. 

Cas looked up at him, his face awash in desire and need and something deeper, something Dean was afraid to name. “Dean,  _ please,”  _ he begged. 

Dean gave a shaky nod then guided the head of his cock to Cas’ entrance. He began pushing in slowly, amazed at how his body just opened up for him and sucked him in. Cas’ hands flew up to Dean's shoulders, his fingers digging into the flexing muscle there and brushing over the raised handprint he had burned into Dean's freckled skin when he had pulled him from Hell. The tendons on his neck stood out in stark relief to the shadows chasing through the windows and his chest flushed a deep red as Dean continued to fill him. 

A low keening wail filtered out of Cas’ throat when he got about halfway in and it absolutely broke Dean. Wave after wave of arousal crashed through him, destroying every last trace of his control. The Alpha in him came roaring to the forefront and he roughly pushed forward on his knees, nearly bending Cas in half when he slid all the way home with that one thrust. 

A jumble of words spilled from Cas’ mouth, some that Dean recognized as  _ yes  _ and  _ Dean  _ and  _ oh god  _ as he began pounding the Omega’s wet, accepting hole. Stretching forward as far as he could, he captured Cas’ lips in a brutal kiss that was more a clash of tongue and teeth than anything else.

Tearing his mouth away after a moment to gasp for breath, Dean marvelled at how well his cock fit inside Cas; it was like they were made for each other, like they were always meant to be together. Dean's heart swelled with the thought and he shoved in faster, wanting nothing more than to knot Cas, to let him feel the warmth and security and relief Dean could and would offer him and surround him with. 

Dean looked down at Cas as he snapped his hips fast and deep, seeing the open vulnerability and trust staring back up at him and all of a sudden there was too much fucking space between them. Dean's nerve endings screamed to feel Cas skin to skin, to feel as much of his body against his own as possible. Sliding Cas’ legs from his shoulders, Dean shoved his arms under Cas’ arching back and pushed up onto his haunches, pulling Cas into his lap in one fluid motion with a guttural growl. 

Cas let out a hitching moan and flung his arms around Dean's shoulders, burying his neck in the crook of Dean's neck. A shudder raced down Dean's spine when he felt the heated wash of Cas’ panted, desperate breaths puffing against his ear. Cas spread his knees wide on either side of Dean's hips, riding Dean's cock with a wild abandon while his dick slid between their bellies. Dean held him close against his chest, pumping up inside Cas as deeply as he could. His hands slipped up Cas’ back, finding their way into his thick, dark hair. 

Two more erratic rises and falls on Dean’s cock and Cas squeezed him tighter, slamming down onto Dean’s lap, his whole body going rigid. “Oh, Dean!” he sobbed. 

Warmth suddenly spread over Dean’s belly as Cas came, spurt over spurt spasming between them, wet and sticky. “That’s it, that’s it,” Dean praised breathlessly.

The broken whimpers filtering from Cas’ throat and the constricting of his insides surrounding Dean’s cock finally sent him over the edge, milking him for everything he had to give. He thrust up into Cas’ welcoming heat one final time, emptying his seed as deep as he could. Locking one hand around Cas’ waist, the other still tangled in his hair, Dean tugged his head back, exposing the Omega’s neck. Cas moaned, continuing to ride Dean’s dick, rolling his hips until Dean was driven out of his goddamn mind. 

Bending his head, Dean scented along the supple muscle between Cas’ neck and shoulder. With no other thought as to what he was doing, he sunk his teeth in, claiming Cas as his own -- something he had never done before in his life. It should have sent a panic through him, doing something so goddamn final, but it felt right, it felt more than fucking right. It was destined to be. 

Pulse after pulse of Dean’s release erupted from his cock, filling Cas to capacity. Dean could feel some of it escape from Cas’ hole and track down his balls and it only made his dick spasm more. Releasing his teeth from Cas’ neck, he rested his forehead against Cas’, his breath coming in harsh and stuttering pants. His cock suddenly began to swell, knotting deep inside Cas, locking them together. 

Cas gasped at the foreign sensation, shifting on Dean’s lap. “Shh. It’s okay,” Dean soothed. “This is supposed to happen.” 

Cas’ arms tightened around his shoulders, nuzzling against Dean’s jaw. “It -- It feels so  _ big,”  _ he rasped, testing the size with a few squirms. 

Dean groaned, holding Cas still. The sudden movement tugged on his knot, sending an indescribable bolt of arousal and pain shooting through him, forcing his cock to release another weak spurt of come inside the Omega. “Try not to move too much, okay?” 

Cas nodded against his neck. “I felt a lot of pressure when I did that. It was not altogether pleasant. How long do we need to stay like this?”

Dean smoothed a hand over Cas’ sweat slick hair, pulling deep breaths of their mingling releases. “Depends,” he answered.

Cas shifted again and they both moaned. “Depends on what?” he asked, obviously doing his best to stay still. 

“On a lot of things. Like how strong the heat is and how long it will take to break it,” Dean explained, trying very hard to control his breathing. It was not easy with how fucking spectacular it felt being inside Cas. 

Cas nodded against his neck, his body temperature already starting to rise again. Dean felt his knot subside a little with the flood of Omega hormones that began to suffuse the room once more and soon Cas started humping him again with little flicks of his hips. Dean’s dick didn’t even get a chance to get soft before he was feeling the familiar tightening low in his belly. 

He was suddenly being pushed down onto his back, with Cas above him, straddling him and leveraging his pushes up and down with his hands flat on Dean’s chest. Dean grasped Cas’ hips, gritting his teeth against the overwhelming conflagration burning through him. He looked up along the beautiful, undulating lines of Cas’ body as he rode him, his eyes suddenly fixating on the raised, red mark he had laid along Cas’ neck. His heart began pounding harder than it already had been -- he had bonded them in only the first round; that was only something true soulmates ever did. 

Dean gulped in a shuddering breath and glanced over to his shoulder, to where Cas had lain a mark of his own on Dean when he pulled him from Hell. His chest tightened inexplicably and he swallowed hard.  

“We share a profound bond, Dean,” Cas panted raggedly, bringing his hand over to brush his fingers along the handprint and then touching those same finger over the mark on his neck. “In more ways than one now. 

Dean smiled up at Cas, driving his hips up hard enough to make Cas gasp. He gripped even tighter to the Omega’s hips as he felt his dick start to swell again. “You do have a point there.”


End file.
